Runtime replacement of processors and runtime replacement of memory modules are two of the key innovative features envisioned in high-end server systems for supporting reliability, availability, and serviceability (RAS). When a processing system supports runtime replacement of processors and memory modules, a faulty processor or memory module can be replaced without shutting down the system. However, it may not be possible to implement runtime replacement of processors and memory modules without providing many different software components in the processing system with special control logic for supporting such functionality. For instance, special control logic may be needed in the applications, in the operating system (OS), and in the device drivers.
When all of the hardware and software for a computer system is built by the same company, that company may be said to provide a vertical solution. Specifically, for purposes of this disclosure, the term “vertical solution” denotes a high-end server with a proprietary OS and vertical device driver and application development environments that are controlled from top to bottom by a single company. A small number of companies may currently build vertical solutions which include the necessary hardware and software features to enable runtime replacement of processors and memory modules. Those companies may include International Business Machines Corp. (IBM), the Hewlett-Packard Company (HP), Sun Microsystems, Inc. (Sun), and NEC Corp. (NEC). However, such a vertical solution is proprietary by nature and does not translate to the horizontal market.
A horizontal solution for this problem needs to run on standard high-volume sewers which use an OS that was designed with standardized interfaces for use in a wide range of platforms. For purposes of this disclosure, an OS that features standardized interfaces for use in a wide range of platforms may be referred to as a shrink-wrapped OS. For example, the various OSs sold by Microsoft Corp. under the Windows trademark are considered shrink-wrapped OSs. The OSs sold by Red Hat, Inc. under the Linux trademark may also be considered shrink-wrapped OSs. For a shrink-wrapped OS, the binaries work with different platforms. Consequently, shrink-wrapped OSs need standardized interfaces, so drivers can be written by parties other than company that wrote the OS.
However, when a data processing system or platform uses a shrink-wrapped OS, that platform may be unable to support runtime replacement of processors or memory modules. Some of the technical challenges associated with creating a platform that supports the runtime replacement of processors or memory modules while using a shrink-wrapped OS pertain to backward compatibility issues with legacy device drivers and applications.